The 'Voice' coach claims "immoral" talent shows such the ITV1 series encourage bullies, and he defended his BBC One show - which also stars Jessie J, Sir Tom Jones and will.i.am on the panel - after recent criticism about the judges' comments to contestants being too upbeat.

He said: "The stance we've taken is that you can deliver bad news in a good way. Maybe it's not great for ratings but we had a 17 year old on our show and she wasn't great. Are we going to destroy her so she couldn't walk down the street? Absolutely not."

But taking a swipe at the 'X Factor' panel - which was made up of Gary Barlow, Tulisa Contostavlos, Louis Walsh and Kelly Rowland in last year's series - he said: "You could have ruined her life if you did to her what other reality shows have done to people.

"If you take this to the schoolyard, what would you say to your kids if they were like 'Off, off, off' to a five year old?

"I'm not there to say 'You're s**t, get off. I give them constructive criticism. I know it doesn't make for good TV.

"I don't want to bring people to tears. Who wants to see a kid cry?"

The 31-year-old singer also suggested some of the judges' remarks on rival talent shows were pre-planned, and admitted he couldn't be an 'X Factor' panellist unless he was allowed to be himself.

He added to The Sun newspaper: "I'm sure on other shows they all sit back and watch the VTs [video tapes] about what's going on that day and decide in the room what to say beforehand.

"We don't. We made a clear decision that the reactions you see are instant ones. I won't play up [to the cameras]. That's not what music is about. Music isn't a pantomime.

"I could only be on 'The X Factor' if I could be me and not have to stick to a particular script."